(a) Field of the Invention
The present invention relates to a method and an apparatus for allocating a resource for a control channel in communication environment (multi-beam environment) using a multi-beam.
Further, the present invention relates to a method and an apparatus for transmitting control information or a control channel in multi-beam environment.
(b) Description of the Related Art
To support the increasing data demand in a mobile communication system, a millimeter wave band in which a wide frequency is easily secured has emerged as a candidate band. The millimeter wave band has a big disadvantage in a path loss but may secure coverage based on a beamforming technique for overcoming the disadvantage.
When the beamforming is used like the system, if the multi-beam is used, capacity of one cell may be increased in proportion to the number of beams. However, when the multi-beam is simultaneously used for a data transmission, data of adjacent beams affect a main transmission beam as interference, which is a cause of performance deterioration. In this case, a control channel that transfers resource allocation information and control information requires a lower error rate than a traffic channel (data channel). Therefore, a method for removing interference or avoiding interference is required.
In the long term evolution (LTE) system, a method for avoiding interference considering an effect of adjacent cells is used. In detail, the method for avoiding interference divides resources based on a frequency base and transmits control information of cells at different resource locations, like an enhanced physical downlink control channel (ePDCCH). In this way, the interference with adjacent cells may be avoided.
In this case, the ePDCCH region is also used simultaneously with using the existing physical downlink control channel (PDCCH) region.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.